In the related art, for example, as described in Patent Literature 1, an external resonator-type semiconductor laser device including a semiconductor laser array in which a plurality of active layers are arranged in a slow axis direction, a collimating lens that collimates laser lights emitted from each of the active layers in a plane perpendicular to the slow axis direction, a first optical element that reflects partial lights advancing to one side in the slow axis direction from among the laser lights emitted from the collimating lens and returns the partial lights to each of the active layers, and a second optical element that reflects partial lights advancing to the other side in the slow axis direction from among the laser lights emitted from the collimating lens and returns the partial lights to each of the active layers is known.